Sometimes a cat just doesn't know when to leave you alone. So what do you do? Artist Brianna had an idea that uses an annoying sound to give her persistent cat the message with her repeller based on an Arduino. It's pretty simple - a passive infra-red sensor detects movement which triggers the Arduino to drive a piezo buzzer for some annoying noises. So when the cat comes near, it sounds and sends the cat elsewhere. A quick demonstration sans cat in the following video:

It's simple, and hopefully it can work with other pets. If you had a cat, it would be wise to change the type of noise every week or so otherwise it would get the better of you and ignore it. Either way, check out Brianna's blog for more information. And we're on twitter and Google+, so follow us for news and product updates as well.

It can be used as a noise-maker driven by your microcontroller for audible feedback of events, and it can also be used as a knock-detector input to sense events and react to them. Includes a built-in 1M resistor to allow the piezo element to detect shocks. For more information and to order, please visit the product page here.